Filling a mesh hole

A computer program product comprising a non-transitory computer-readable storage medium having computer-readable program code embodied therewith for filling a mesh hole in a mesh of a 3D digital model resulting from a scan of a 3D physical structure to enable manufacturing of a 3D physical copy, the mesh comprising a plurality of vertices, the mesh further defining a plurality of edges,

• a boundary of the mesh hole being provided by a first closed boundary curve comprising boundary edges connecting boundary vertices of a first plurality of boundary vertices, the first plurality of boundary vertices comprising a first number of boundary vertices, with the first number of boundary vertices being four or more,
• wherein the filling comprises:
• acquiring scan data of the 3D physical structure by scanning the 3D physical structure using a scanner, the acquired scan data being descriptive of a 3D geometrical form of a surface of the scanned 3D physical structure,
• providing the mesh of the 3D digital model of the 3D physical structure with the mesh hole using the acquired scan data of the 3D physical structure, wherein the 3D digital model is a digital replica of the scanned 3D physical structure and the mesh resembles the 3D geometrical form of the surface of the scanned 3D physical structure,
• determining for each pair of boundary vertices of the first plurality of boundary vertices a maximized triple resulting in a plurality of maximized triples for all pairs of boundary vertices of the first plurality of boundary vertices, wherein the determining of the plurality of maximized triples comprises for each pair of boundary vertices determining an additional boundary vertex of the first plurality of boundary vertices for which an angle between vectors from the determined additional boundary vertex to the boundary vertices of the respective pair of boundary vertices is larger than for using any other boundary vertex of the first plurality of boundary vertices as the additional boundary vertex,
• selecting from the plurality of maximized triples a maximized triple of boundary vertices comprising a first, a second and a third boundary vertex of the first plurality of boundary vertices without a single edge connecting the first and second vertex,
• wherein the selected maximized triple is maximized by selecting a boundary vertex of the first plurality of boundary vertices as the third boundary vertex of the selected maximized triple such that a maximized angle between a first vector from the third boundary vertex to the first boundary vertex and a second vector from the third boundary vertex to the second boundary vertex is maximized compared to selecting any other boundary vertex of the first plurality of boundary vertices as the third boundary vertex,
• wherein the selected maximized triple satisfies a first selection criterion, the first selection criterion requiring the maximized angle to be smaller than or equal to 90°,
• connecting the first and the second vertex of the selected maximized triple of boundary vertices using a connecting curve from the first to the second boundary vertex,
• generating a 3D digital template based on the 3D digital model, and manufacturing the physical 3D copy of the 3D digital template.

A computer system for filling a mesh hole in a mesh of a 3D digital model resulting from a scan of a 3D physical structure to enable manufacturing of a 3D physical copy, the computer system comprising a processor and a memory storing machine-executable program instructions,

• the mesh comprising a plurality of vertices, the mesh further defining a plurality of edges, a boundary of the mesh hole being provided by a first closed boundary curve comprising boundary edges connecting boundary vertices of a first plurality of boundary vertices, the first plurality of boundary vertices comprising a first number of boundary vertices, with the first number of boundary vertices being four or more,
• execution of the program instructions by the processor causing the processor to control the computer system to:
• acquire scan data of the 3D physical structure by scanning the 3D physical structure using a scanner, the acquired scan data being descriptive of a 3D geometrical form of a surface of the scanned 3D physical structure,
• provide the mesh of the 3D digital model of the 3D physical structure with the mesh hole using the acquired scan data of the 3D physical structure, wherein the 3D digital model is a digital replica of the scanned 3D physical structure and the mesh resembles the 3D geometrical form of the surface of the scanned 3D physical structure,
• determine for each pair of boundary vertices of the first plurality of boundary vertices a maximized triple resulting in a plurality of maximized triples for all pairs of boundary vertices of the first plurality of boundary vertices, wherein the determining of the plurality of maximized triples comprises for each pair of boundary vertices determining an additional boundary vertex of the first plurality of boundary vertices for which an angle between vectors from the determined additional boundary vertex to the boundary vertices of the respective pair of boundary vertices is larger than for using any other boundary vertex of the first plurality of boundary vertices as the additional boundary vertex,
• select from the plurality of maximized triples a maximized triple of boundary vertices comprising a first, a second and a third boundary vertex of the first plurality of boundary vertices without a single edge connecting the first and second vertex,
• wherein the selected maximized triple is maximized by selecting a boundary vertex of the first plurality of boundary vertices as the third boundary vertex of the selected maximized triple such that a maximized angle between a first vector from the third boundary vertex to the first boundary vertex and a second vector from the third boundary vertex to the second boundary vertex is maximized compared to selecting any other boundary vertex of the first plurality of boundary vertices as the third boundary vertex,
• wherein the selected maximized triple satisfies a first selection criterion, the first selection criterion requiring the maximized angle to be smaller than or equal to 90°,
• connect the first and the second vertex of the selected maximized triple of boundary vertices using a connecting curve from the first to the second boundary vertex,
• generate a 3D digital template based on the 3D digital model, and
• manufacture a physical 3D copy of the 3D digital template.